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With increasing demand and environmental concerns, researchers are exploring new materials that can perform as well or better than traditional materials while reducing environmental impact. X-ray absorption spectroscopy (XAS) enables unique atom-specific tool to probe the electronic structure of materials. The BAM plays a central role in this highly collaborative research. The BAMline, a real-life sample materials research beamline, at the Berlin Synchrotron BESSY-II, provides unique insights into materials’ electronic and chemical structure at different time and length scales. This enables real-time optimization of material properties and performance for various applications, such as energy storage and conversion, catalysis, and corrosion resistance. This talk provides an overview of the analytical methods and sample environments of the BAMline and addresses its potential for further advances in sustainable materials research.
Ziele der Jungen GfKORR
(2024)
Die Junge GfKORR soll ein attraktives Angebot für junge Leute sein, sich fachübergreifend zu vernetzen und einen Einstieg in Querschnittsthemen bieten. Sowohl der Korrosionsschutz zum Zwecke der Nachhaltigkeit und Sicherheit von Bauwerken als auch der Korrosionsschutz bei Energie- und Mobilitätssystemen soll in zukünftigen Veranstaltungen übergreifend betrachtet werden. Dabei wollen wir den fachlichen und informativen Input aus den Arbeitskreisen der GfKORR bei unseren Seminaren suchen. In diesem 1. Netzwerk- und Arbeitstreffen wurde die Fahrtrichtung der Jungen GfKORR genauer abgesteckt und es hat sich eine Leitungsebene gefunden. Weiter wollen wir ab 2024 interessante Präsenzveranstaltungen mit Exkursionen anbieten.
Die Anforderungen in verschiedenen Fachgebieten des Bauwesens an metallene Befestigungsmittels hinsichtlich des Korrosionsschutzes sind zum einen Abhängig von den verwendeten Werkstoffen und zum anderen von der Korrosivität in der jeweiligen Exposition. Hier wird ein Überblick über die gängigen Werkstoffe als auch Anwendung und Fehlerquellen verschaff
Often corrosion rates are determined to get an idea of the corrosivity of the atmosphere. The calculated mass loss does not reflect the ingress of metal ions into the environment. Therefore, the runoff project was started to determine the metal ion ingress with respect to rain events for zinc and copper.
Formation of Corrosion Product Layers on Galvanized Reinforcement in Chloride Containing Mortar
(2024)
To study a corrosion system such as galvanized steel in chloride containing mortars, more than just some electrochemical studies are required. The addition of chlorides by direct addition to the water will have an influence on the hardening process and consequently on the pore structure, and the investigation of these influences is necessary.
Furthermore, a new approach has been investigated which is able to determine the corrosion rate in less than 30 seconds without influencing the corrosion system by intense polarization.
To determine the corrosivity of atmospheric conditions, standardized metal sheets are exposed. After pickling, the loss of mass indicates the corrosivity of the atmospheric conditions. Under marine conditions, a sheltered opportunity will mirror the situation where e.g. chlorides could accumulate on the surface because they are protected from rain. Under these conditions, the corrosivity could be even higher than under free weather conditions. These sheltered conditions are necessary for a realistic service life prediction.
Electrochemical potential mapping is a recognized technique for the localization of corroding reinforcing steels. Areas of corroding reinforcement steel can be located in a non-destructive manner by means of this procedure. Half‐cell potential measurements are used in order to detect chloride‐induced corrosion. However, it is not recommended in order to assess the risk of carbonation‐induced corrosion. For this purpose, determining the carbonation depth and the concrete cover appears more appropriate. The content of this specification exclusively refers to the application of mobile, local variable reference electrodes, which are only placed on the concrete surface while measuring. The technique distinguishes itself thereby from the range of corrosion monitoring systems with stationary installed reference electrodes and sensor systems, respectively, whereby it is possible to continuously track measurements within the area of the installed electrodes. However, these methods are not dealt with in this specification.
The efficient exploration of novel alloy compositions is crucial for advancing the development of new materials. One widely utilized approach for creating phase diagrams is the use of diffusion-controlled synthesis for gradient alloys. This method is also an effective means for rapidly identifying potential material combinations.
The present study focusses on the exploration of quaternary multi-principle-element alloys (MPEAs) using diffusion multiples. We established a diffusion system by combining an equimolar ternary alloy (FeNiCr) with single diffusing elements Mn and Mo. Using ThermoCalc simulations, we determined suitable temperature ranges where we can expect the formation of single-phase alloys. Depending on the diffusion constants of the selected metals, diffusion times were adjusted to obtain diffusion zones with a depth of greater than 50 μm. Microstructural and compositional information was gathered via scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) and correlated to local mechanical properties evaluated by means of nanoindentation. Local corrosion properties were examined using Atomic Force Microscopy (AFM) and Scanning Electrochemical Microscopy (SECM).
Our results indicate that the ThermoCalc simulations have a good predictive power for crystallographic phases. However, especially with the Mn-FeNiCr system, formation of Cr-rich secondary phases were observed, which led to Cr-depletion and thus to localized corrosion processes in the matrix at the vicinity of the secondary phases. Based on the results of the local electrochemical tests, we have selected single-phase compositions along the diffusion zone and synthesized these alloys in bulk for corrosion studies by means of potentiodynamic polarization and SECM.
The presentation will summarize our methodology using diffusion couples as an
efficient tool for exploring compositional spaces of MPEAs in the search for novel single-phase alloys and the results of our correlative study on the mechanical and corrosion properties of these materials.